Android: Write all proguard flags to out.jar.flags file

build/android/gyp/util/proguard_util.py

 # Copyright 2015 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import os
 import re
 from util import build_utils
 
 
 class _ProguardOutputFilter(object):
@@ skipping 133 matching lines @@
     self.build()
     inputs = [self._proguard_jar_path] + self._configs + self._injars
     if self._mapping:
       inputs.append(self._mapping)
     if self._libraries:
       inputs += self._libraries
     if self._tested_apk_info_path:
       inputs += [self._tested_apk_info_path]
     return inputs
 
+  def _WriteFlagsFile(self, out):
+    # Quite useful for auditing proguard flags.
+    for config in self._configs:
+      out.write('#' * 80 + '\n')
+      out.write(config + '\n')
+      out.write('#' * 80 + '\n')
+      with open(config) as config_file:
+        out.write(config_file.read().rstrip())
+      out.write('\n\n')
+    out.write('#' * 80 + '\n')
+    out.write('Command-line\n')
+    out.write('#' * 80 + '\n')
+    out.write(' '.join(self._cmd) + '\n')
 
   def CheckOutput(self):
     self.build()
     # Proguard will skip writing these files if they would be empty. Create
     # empty versions of them all now so that they are updated as the build
     # expects.
     open(self._outjar + '.seeds', 'w').close()
     open(self._outjar + '.usage', 'w').close()
     open(self._outjar + '.mapping', 'w').close()
+
+    with open(self._outjar + '.flags', 'w') as out:
+      self._WriteFlagsFile(out)
+
     # Warning: and Error: are sent to stderr, but messages and Note: are sent
     # to stdout.
     stdout_filter = None
     stderr_filter = None
     if not self._verbose:
       stdout_filter = _ProguardOutputFilter()
       stderr_filter = _ProguardOutputFilter()
     build_utils.CheckOutput(self._cmd, print_stdout=True,
                             print_stderr=True,
                             stdout_filter=stdout_filter,
                             stderr_filter=stderr_filter)
 
     this_info = {
       'inputs': self._injars,
       'configs': self._configs,
       'mapping': self._outjar + '.mapping',
     }
 
     build_utils.WriteJson(this_info, self._outjar + '.info')